Welcome to the Darrouzet-Nardi Lab homepage!
I am currently recruiting students for two funded Ph.D. positions. Please see this page for more information. Please note that though the application date for the UTEP graduate program is in early February, there is flexibility in the admissions process, particularly if you are a strong candidate.
ABOUT THE LAB: I am an assistant professor in the Biological Sciences department at the University of Texas at El Paso. I started at UTEP in January of 2015 and my research lab is growing quickly! The goal of my research is to use ecological field experiments to discover and describe the plant and soil processes that drive the function of terrestrial ecosystems, especially in mountains, deserts, and the Arctic tundra. Many of our projects also include a global change component such as the effects on ecosystem function of invasive species, air pollution, or climate change.
GOOD NEWS: I recently found out that one of our major grant proposals has been funded by the National Science Foundation. Starting in spring 2016, we will be setting up a multi-site experiment to study the fungal loop in desert ecosystems. More specifically, we will be looking at subterranean fungal connections between biological soil crusts (don't bust the crust!) and plants in three different deserts: the Chihuahuan desert near El Paso, the Colorado Plateau near Moab, and, between those, the Sevilleta LTER near Albuquerque. There are a bunch of collaborators and opportunities for students and cool science to be done so we are really excited!
PROSPECTIVE STUDENTS: There are great opportunities for graduate students to work on the recently funded grant and other lab projects. I am actively looking for talented graduate students, so please contact me if you are interested in joining my lab! More info on the grant project here and more general info for prospective students here.
Department of Biological Sciences
500 W. University Ave.
University of Texas at El Paso
El Paso, TX 79968
Office: Biology B401
Lab: Biology B419
Pronunciation of Darrouzet: DARE-uh-zet
Climate change in dryland ecosystems
Just before I came to UTEP, I worked on biological soil crust (biocrust) responses to elevated temperature and changing precipitation. Our analyses of the net exchange of carbon between biocrusts and the atmosphere in a multiyear 2°C warming experiment (infrared heat lamps) showed increased carbon losses in the warming treatment, suggesting negative impacts of warmer future climates on biocrusts. We also discovered these crusts can perform photosynthesis under snow despite living in the desert.
Changing seasonality of plant-soil interactions in the Arctic tundra
Arctic soils contain large stocks of carbon and may be a significant CO2 source in response to climate change. Using an early-snowmelt×warming manipulation at a site near Toolik Field Station on Alaska's North Slope, our team investigated changes in soil nutrient cycling in response to changing climate and seasonality. Our results showed that snowmelt acceleration causes more rapid early-season nutrient immobilization in soils and that early snowmelt in unwarmed plots can cause season-long reductions in root growth and inorganic N availability due to plant exposure to harsh conditions in the absence of snow.
Landscape heterogeneity of nitrogen cycling in an alpine-subalpine ecosystem (Dissertation)
Microbially mediated nitrogen cycling rates are heterogeneous across landscapes, with disproportionate activity occurring in biogeochemical hot spots. My dissertation examined landscape heterogeneity in soil nitrogen (N) cycling pools and fluxes in a 0.89 km2 site at the alpine-subalpine ecotone. My data showed that a large percentage of total inorganic N pool sizes and associated cycling rates were attributable to a small percentage of hot spots. We also discovered a spatially inverse relationship between atmospheric N deposition and N-fixing plant abundance.
Sagebrush encroachment in subalpine meadows of the Sierra Nevada Mountains
Over the last 100 years, sagebrush shrubs (Artemisia rothrockii) have encroached into subalpine meadows in the Sierra Nevada Mountains due to groundwater decline associated with livestock grazing. We discovered that sagebrush transpiration does not dry out the soil during encroachment as we hypothesized it might. Using stable oxygen isotopes, we also showed that both young sagebrush plants and resident herbs used shallow soil water but were also able to access deeper water. Nutrient cycling rates increased with shrub encroachment.